Counterbalancing device



June 3, 1941. a BALL 2 ,243,940

COUNTERBALANC ING DEVI CE Original Filed June 16, 1959 3 Sheets-Sheet 1 4 Ber/zcird A, Ball.

June 3, 1941. B. A. BALL GOUNTERBALANCING DEVICE 3 Sheets-Sheet 2 Original Filed June 16, L939 UJJ rail .481. Ball.

Ber

June 3, 1941. BALL 2,243,940

COUNTERBALANCING DEVI CE Original Filed June 16, 1939 s Sheets-Sheei a I l I 1 i I L- l M Li 3mm Ber/WA. Ball Patented June 3, 1941 UNITED STATES PATENT OFFICE,

1940, Serial No. 331,035

3 Claims.

This application is a division of my earlier application for patent, Serial No. 279,547, filed June 16, 1939, for Tenpin setting machines, and relates particularly to counterbalancing devices adapted for use with such machines, although this invention has more general application as well.

The principal object of the invention, therefore, is to produce a better and more active mechanism for returning the frames of tenpin setting machines to their elevated or normal positions.

Figure 1 is a perspective View of a portion of a 'tenpin setting machine, looking at it from the left front, and showing the counte-rb-alan'cing device applied thereto.

Figure 2 is a view, partly in section, of the counterbalancing roller and its immediately cooperating parts.

Figure 3 is a view of the inside of one of the side frames, with the counterbalancing device in section, the figure being taken on the line 33 of Fig. 1, looking in the direction of the arrows.

Although, as stated above, the invention is of general application, it will herein be described in connection with a tenpin setting machine.

' Only enough of the machine, however, is shown as is necessary to illustrate the construction and operation of the counterbalance.

The pin carrier or platform proper is in general of the same construction as that shown in the patent to Backus No. 809,890, granted January 9, 1906. This has been long and successfully used, and need not be illustrated'or described in detail. For. the purpose of this case, it is sufficient to say that it consists primarily of a platform ||l adapted to carry the pins and provided with guides 2 pivoted to the platform, by which the pins are guided to the alley.

As heretofore constructed, pin setting machines have usually been provided with counterbalancing weights for restoring their pin platforms to normal or raised position. These weights must have a mass sufficient to overbalance and thus lift the pin platform when empty, after the tenpins have been deposited on the alley. But the action of all counterweights is sluggish, for they operate according to the laws of gravity, and so always start slowly and move with a continuously accelerated motion. In the construction of the instant case, torsion springs have been used in place of the weights of earlier machines. Springs, when under constant tension, as they will here be in practice, beginto exert their full lifting force as soon as released, and therefore are quicker in Divided and this application April 22,

action than weights, which operate only by gravity.

Referring to the drawings, and particularly to Fig. 2 thereof, 20 is a shaft suitably mounted for rotation in the frame of the machine, and 2| is a drum or sleeve surrounding the shaft 2|] and rotatable thereon. On shaft '20 are mounted helical springs, as 22 and 26. Any number of such springs may be used. Only two are shown here, and they are illustrated as reversely wound with respect to each other; that is, they are wound one to the right and the other to the left. One end of each spring, as here shown the inner end, is fastened directly or indirectly to the shaft 20; and while this may be done in any preferred manner, I have shown the inner end 23 of the spring 22 formed into a loop 24, and the inner end 2'! of the spring 26 formed into a similar loop 28, and these loops respectively secured to the shaft 20 by screws or bolts 25 and 29 which pass through the loops and into or through the shaft 20. The other ends of the springs 22 and 26 are secured to the drum 2 I, the outer end of the spring 22 being secured to the drum 2| .by a

' nut 32 and the outer end of the spring 26 being secured to the drum 2| by the nut 35. The specific means for securing the ends of the springs to the shaft 2|] and the drum 2| are not of the essence of the invention, and other desired means may be employed.

Cords or cables 36 and 31, of wire or other suitable material, are provided to support the pin platform. One end of each of these cables is secured to the platform, while the other end of each cable is wound directly upon the drum 2|, if the same be of sufficient size, or upon an auxiliary drum, as 38 or 39, secured to the drum 2|.

The drum or sleeve 2| is mounted on the shaft 20 by means of collars; in Fig. 2, the right hand end of the drum is secured to a bushing 45, which in turn is mounted for free rotation on the shaft 20, and the left hand end is secured to a bushing 46, which likewise is mounted to rotate freely on shaft 26. As here shown, a washer 41 of suitable thickness is placed between the bushing 46 and the left hand end of the frame of the machine. A collar 48, secured on the right hand end of the shaft 20, and outside the frame, prevents the end of the shaft from slipping through the frame.

On the left hand end of the shaft 20, Figs. 1 and 2, is arranged a ratchet wheel 50, having on the periphery thereof teeth 5|, and secured to the shaft 20 in any convenient way, as by a pin ,52, so as to turn with the shaft. A lever53,

"leys, usually termed kickbacks.

carrying a floating pawl 54, is rotatably mounted on the hub 55 of the ratchet wheel 50; and a holding pawl 56, pivoted at 51, cooperates with the ratchet teeth to hold the ratchet against rotation. One end of the shaft 20 is shaped as at 58 to receive a wrench for turning the shaft, so that the springs '22 and 26 may be put under tension. In practice, the approximate tension is put upon the springs 2-2 and .26 by the use of this wrench; but the shaft may also be turned by the lever 53 and floating pawl 54, and minor adjustments are usually made in this manner. The shaft is held in the desired position by means-- of the holding pawl 56. V

The rotation of the shaft 20, either by means of the squared head 58 orby theleVer'and pawl 53, 54, will simultaneously put tensio-n-on-both springs. In practice, the springs should be so tensioned that they will be able to lift the pin platform quickly and positively when the platform is unloaded-but will permit the platform when carrying the pins to fall freely of its own weight, or with only slight additional pressure by the'operator. Experience must determine the proper tension.

'By this construction, the main operating 'VVhile the springs are here shown as connected to the shaft *ZIl at their inner ends, and to the drum? I at'their outer ends, it is to beunderstood that of course this arrangement may be reversed, and the outer ends connected to the shaft and the inner ends to the sleeve.

As stated above, the counterbalancing device herein described and claimed, while of general application, is shown inconjunction 'with a ten- :pin setting machine. --merely to illustrate the invention, and'is not This machine is used claimed herein,'but is describedand claimed'in "said parent application Serial No. 279,547,'filed June 16, 1939, of 'which this-is a division. It will,

however, be well to describe the machine shown inigeneral terms.

The pin setter comprises, in .general,"two"side frames, each constructed, as here shown, of -Z-iron' uprights I! "and F52, and crosspieces-'63 and fid. Theremay be as many crosspieces as necessary, but only two are shown in the drawings. The top crosspieces (53' are each provided with-an'enlargement orexterision 65, through which the shaft .20 of the counterbalancing -me'anspasses. The collar 33011 the shaft seoperates with the outer face of this enlargement -65 on the right hand side of the machinefFig. 2, while-the ratchet wheel bii is secured to the end --of the'shaft outside the extension'lili at the other side of the machine. I

These side frames maybe supported in any "convenient way relative to the alley, but are here shown assupported by-tlie divisions between al- The supporting devices are in the nature of brackets III having their upper ends attached to the Z-irons' of the frame and their lower ends secured to'thekickthattheybe heredescribed further; I j Abeam-tfi, Fig 1'; connects the two-side frame andis T secured "thereto in any suitable-way.

again at 95, so as to offset the lower ends thereof 7 for a purpose to be later explained.

Arranged to slide on each side frame are supplemental frames comprising members I00, IDI,

and crosspieces I92 and I03, with diagonal braces "I04 and I05.

To these supplemental frames are secured brackets I I I which support the pin platform proper. Thus, as the supplemental slides are'moved up and down in the frames, the bracketswhich aresecured thereto carry the pin plat- -form Illin its movements toward and away from the alley. The construction of the supplemental slides and of the guideways therefor is novel, but s'ince'this arrangement is not involved in this ap- -plication, it is not necessary that it be more particularly described.

In orderto lower and raise the' pin platform manually, or-to-aid in the lowering and lifting of the sameya manual operating mechanism is shown in Figs. 2 and 3. It is necessary in pin setting machines to have some such supplemental operating mechanism, because the weight carried by the'platform may vary greatly under operating conditions. If the'counterbalancing mechanism is adjusted-t0 take care of the whole complement of pins, it will not function properly "when themachine is operated with only a por- I30 running across the upper portion of the frame where-it can be conveniently grasped by "the operator.

This'bar has rollers I3I, one on each end thereof, normally resting onwear plates I32'secured'to the" sideframes of the machine. Bars I33 one' on the inside of each side frame are attached at their "outer ends to the'bar I38,

and have their other'ends' mounted withasliding "connectionon the low'en'erids of th bars 92.

This sliding connection is'rnerely' an elongated slot-I34'and pin connection I35. Each auxiliary slidingfram e hasattached thereto a channel bar "i 36, --'or its -equiva1ent,-and 'operatingin-- each channelis an antifriction roller I38," carried by and pivoted on the bar i33 These rollersf as the handle it 9 moved up" and down, move back and forth in the channelsl ib. g Normally, thepin platform lt is in raised position, being held in this position both i by the tension of the springs and by'the locking-action of the-handle bar upon thewearplates. =As- 'suming the i'pin-platfor-m to -be loaded, if the handle 'bar I3tis drawn "off the Wear plates I 32, the pin platform II) will move -down of its own weight, and simultaneously will w'ind' up the tor- 'sio-n springs 22 and 26. "'When' "the pins shall have beendeposited -on5the alley; the pin platform-{due to 'the extra tensionput uponthe torsion springs 22 and 26, and the'loss of 'the *pin load, will be "automatically raised by the springs until 'the handlebar-4% reaches its highest-positio-n, and its' en'd's come to re'st on the wear plates I32; -But 'if the 'pin' platform doesnot have upon it a' -full compiementcrpins; and the handlebar 1 30 is moved-en the wear plates I32, 1 theweight or thepin platfdr m to'ge'th'er with the weight *or the pins will not be sufficient to lower the platform against the tension of the torsion springs, and it Will then be necessary not merely to draw off the handle set but to press down on the same, and thus efiect the positioning of the pins manually.

As the handle bar I35 moves down and up, it is to be understood that the rollers I38 carried by the arms I33 move back and forth in the channel bars I35, and in so doing lower and raise the supplemental side frames, which, in turn, through the brackets i l lower and raise the pin platform.

The springs I48), of which two are shown, are buffers for absorbing the shock of the pin platform and associated parts as the platform is returned to raised position.

Having now described the principles of my invention, I claim:

1. A counterbalancing mechanism comprising a shaft normally stationary but adapted to be turned, a drum surrounding the shaft and mounted to rotate with respect thereto, load supporting means adapted to be wound upon the drum, a

plurality of helical springs surrounding the shaft and within said drum and having their ends secured to axially spaced points on the drum and shaft respectively, so that a relative movement of the shaft and the drum in one direction will simultaneously tension all of the springs, and i the springs when not restrained will provide a relative movement of the shaft and the drum in the other direction.

2. A counterbalancing mechanism comprising a shaft normally stationary but adapted to be turned, a drum surrounding the shaft and mounted to rotate with respect thereto, load supporting means adapted to be Wound upon the drum, a pair of oppositely wound helical springs surrounding the shaft and Within said drum, adjacent ends of the oppositely wound springs being secured to the shaft and the other ends of the springs being secured in axially spaced relation to the drum, so that a relative movement of the shaft and the drum in one direction will simultaneously tension all of the springs, and the springs when not restrained will provide a relative movement of the shaft and the drum in the other direction.

3. A counterbalancing mechanism comprising a shaft normally stationary but adapted to be turned, a drum surrounding the shaft and mounted to rotate with respect thereto, load supporting means adapted to he wound upon the drum, helical springs in oppositely wound pairs surrounding the shaft and within said drum, and means for turning the shaft to vary the tension in the springs and means for locking the shaft to hold the springs under tension, adjacent ends of the springs of each pair being secured to the shaft in axially spaced relation to the adjacent ends of each other pair and the opposite ends of the springs of each pair being secured in axially spaced relation to the drum, so that a relative movement of the shaft and the drum in one direction will simultaneously tension all of the springs, and the springs when not restrained will provide a relative movement of the shaft and the drum in the other direction.

BERNARD A. BALL. 

